Fundus imaging apparatus

ABSTRACT

Provided is a fundus imaging apparatus which achieves reduction of a load on an examiner by facilitating understanding of an operation of switching from a fundus imaging mode to an anterior ocular segment imaging mode, comprising: an imaging unit for taking an image of an eye to be inspected; a focusing unit for achieving a substantially conjugate relationship between the eye to be inspected and the imaging unit; a diopter adjustment unit for adjusting a diopter when the eye to be inspected is myopic or hyperopic; an imaging selecting unit capable of selecting the fundus imaging mode or the anterior ocular segment imaging mode; a diopter adjustment switching unit for switching the diopter adjustment unit in accordance with the selected imaging mode; and a drive unit for driving the focusing unit in accordance with the selected imaging mode.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a fundus imaging apparatus, and moreparticularly, to a fundus imaging apparatus capable of imaging ananterior ocular segment of an eye to be inspected.

2. Description of the Related Art

Conventionally, there has been known a fundus camera capable ofobserving and imaging a fundus and an anterior ocular segment of an eyeto be inspected. A fundus camera disclosed in Japanese PatentApplication Laid-Open No. H04-317628 supports imaging of the anteriorocular segment as well by spacing the eye to be inspected away from thefundus camera, and moving a focus lens for focusing between an image ofthe eye to be inspected and an imaging plane in a hyperopic directionwhen imaging the anterior ocular segment.

In a case where an examiner such as an ophthalmologist uses the funduscamera as described above for imaging the anterior ocular segment, theexaminer first switches a diopter adjustment lens to a hyperopia lens,and moves the focus lens in the hyperopic direction. Then, the examinergreatly moves the fundus camera toward the examiner side. Finally, theexaminer performs alignment for imaging the anterior ocular segment ofthe subject, and then performs imaging of the anterior ocular segment.

As described above, in the fundus camera capable of imaging the anteriorocular segment as well, there is a problem in that the switching fromthe fundus imaging mode to the anterior ocular segment imaging mode isextremely complicated, hard to understand, and time consuming. Toaddress this problem, in a fundus camera disclosed in Japanese PatentApplication Laid-Open No. H08-275921, in order to image the anteriorocular segment, an imaging optical system for the anterior ocularsegment is separately provided, which allows imaging of the anteriorocular segment. However, the apparatus increases in size andmanufacturing cost.

Further, in an ophthalmologic imaging apparatus disclosed in JapanesePatent No. 4,430,378, a moving amount per unit rotational angle of afocus knob is changed between the case of imaging the fundus and thecase of imaging the anterior ocular segment. Accordingly, in the case ofimaging the anterior ocular segment, the focus lens can be movedgreatly, and hence it is expected that the period of time required forthe switching from the fundus imaging mode to the anterior ocularsegment imaging mode can be reduced to a certain extent. However, it ishard to say that the examiner's operation is reduced.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above-mentionedproblems, and it is therefore an object of the present invention toprovide a fundus imaging apparatus capable of reducing a load on anexaminer and reducing a period of time required for switching from afundus imaging mode to an anterior ocular segment imaging mode byfacilitating understanding of a switching operation and simplifying theswitching operation.

A fundus imaging apparatus according to the present invention includes:an imaging unit for receiving reflected light from an eye to beinspected through an optical system to take an image of the eye to beinspected; a focusing unit for achieving a substantially conjugaterelationship between the eye to be inspected and the imaging unit; adiopter adjustment unit for adjusting a diopter when the eye to beinspected is myopic or hyperopic; an imaging selecting unit capable ofselecting one of a fundus imaging mode, in which a fundus of the eye tobe inspected is imaged, and an anterior ocular segment imaging mode, inwhich an anterior ocular segment of the eye to be inspected is imaged; adiopter adjustment switching unit for switching the diopter adjustmentunit in accordance with the one of the fundus imaging mode and theanterior ocular segment imaging mode selected by the imaging selectingunit; and a drive unit for driving the focusing unit in accordance withthe one of the fundus imaging mode and the anterior ocular segmentimaging mode selected by the imaging selecting unit.

According to the present invention, the load on the examiner can bereduced and the period of time required for the switching from thefundus imaging mode to the anterior ocular segment imaging mode can bereduced by facilitating understanding of the switching operation.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a configuration of a non-mydriaticfundus camera according to embodiments of the present invention.

FIG. 2 is a view of an appearance of a switching selecting portionaccording to the embodiments of the present invention.

FIG. 3 is a schematic diagram illustrating a configuration of a diopteradjustment switching portion according to the embodiments of the presentinvention.

FIG. 4 is an overall view of the non-mydriatic fundus camera.

DESCRIPTION OF THE EMBODIMENTS

Hereinbelow, exemplary embodiments of the present invention aredescribed with reference to the attached drawings. In the embodiments ofthe present invention, description is given by using a non-mydriaticfundus camera as a fundus imaging apparatus.

First Embodiment

FIG. 1 is a diagram illustrating a configuration of the non-mydriaticfundus camera.

The fundus camera includes a lens 4, a relay lens 11, a relay lens 12,and a cornea stop 13 having a ring-like opening portion, which arearranged in order on an optical path ranging from a near-infrared LED 8serving as an observation illumination light source to an objective lens1 through a perforated mirror 2. The lens 4 has a function of enhancingeffectiveness of utilizing light emitted from the near-infrared LED 8.Further, the cornea stop 13 separates an illumination light beam from animaging light beam so as to prevent adverse light (reflected light) froma cornea of an eye E to be inspected due to the illumination light beamfrom entering an imaging stop 15.

Further, the fundus camera includes a lens 5, a pupil stop 14 having aring-like opening portion, and a crystalline lens stop 7 having aring-like opening portion, which are arranged in order on an opticalpath ranging from a xenon tube 3 serving as an imaging light source to amirror 6 arranged between the relay lens 11 and the lens 4. The xenontube 3 is a stroboscopic light source for emitting flashes of visiblelight, and a visible light LED may be used instead. The lens 5 has afunction of enhancing effectiveness of utilizing light emitted from thexenon tube 3. Further, the pupil stop 14 is arranged substantially at aconjugate position with the eye E to be inspected. The crystalline lensstop 7 separates the illumination light beam from the imaging light beamso as to prevent adverse light (reflected light) from a crystalline lensof the eye E to be inspected due to the illumination light beam fromentering the imaging stop 15.

Such an optical system ranging from the near-infrared LED 8 serving asthe observation illumination light source and the xenon tube 3 servingas the imaging light source to the objective lens 1 through theperforated mirror 2 constitutes an illumination optical system.

In the rear of the perforated mirror 2, the imaging stop 15, a focuslens 20 serving as a focusing unit, an imaging lens 21, and an imagingportion 22 are arranged. The imaging portion 22 is an imaging elementsuch as a CCD, and is capable of receiving light of an image of the eyeto be inspected. Further, the imaging portion 22 has a sensitivity thatcovers a visible light range and an invisible (near-infrared) lightrange, and is capable of outputting a moving image and a still image.

Such an optical system ranging from the objective lens 1 to the imagingportion 22 constitutes an observation/imaging optical system.

Further, the fundus camera includes a control portion 41 for controllingthe entire system, a drive portion 31, an imaging switch 42, and amonitor 30. The above-mentioned imaging portion 22, drive portion 31,and imaging switch 42 are each connected to the control portion 41.

The drive portion 31 moves the focus lens 20 in an optical axisdirection based on an instruction of the control portion 41. The imagingswitch 42 is a switch to be pressed by the examiner when the examinerinstructs the control portion 41 to perform imaging. Further, themonitor 30 is connected to the imaging portion 22, and the examinertherefore displays an output image signal of a moving image or a stillimage taken by the imaging portion 22.

In the fundus camera of this embodiment, the examiner can switch betweena fundus imaging mode and an anterior ocular segment imaging modethrough a switching operation portion serving as an imaging selectingunit. First, a case where the fundus imaging mode is selected in thefundus camera is described.

[Fundus Imaging Mode]

In the case where the fundus imaging mode is selected, the near-infraredLED 8 emits light to irradiate the fundus of the eye E to be inspectedthrough the illumination optical system. Reflected light from the fundusof the eye E to be inspected is imaged on the imaging portion 22 throughthe observation/imaging optical system. The reflected light from thefundus is focused on the imaging portion 22 by the control portion 41moving the focus lens 20 in the optical axis direction through the driveportion 31 in accordance with an operation performed by the examinerthrough a focus operation portion (not shown). Further, the examinerperforms alignment of the fundus of the eye E to be inspected byoperating an alignment operation portion (not shown) provided to thefundus camera.

Further, there are cases where the subject is highly myopic and wherethe subject is highly hyperopic conversely. In those cases, focus cannotbe achieved within the movable range of the focus lens 20.

The fundus camera of this embodiment includes a diopter adjustmentswitching portion 24 for inserting a diopter adjustment portion 18 intothe observation/imaging optical system. The diopter adjustment switchingportion 24 includes a high-myopia diopter adjustment lens 17 and ahigh-hyperopia diopter adjustment lens 16 as the diopter adjustmentportion 18.

In the case where the subject is highly myopic, the diopter adjustmentswitching portion 24 inserts the high-myopia diopter adjustment lens 17into the observation/imaging optical system in accordance with anoperation performed by the examiner through a switching operationportion 25.

On the other hand, in the case where the subject is highly hyperopic,the diopter adjustment switching portion 24 inserts the high-hyperopiadiopter adjustment lens 16 into the observation/imaging optical systemin accordance with an operation performed by the examiner through theswitching operation portion 25.

The examiner performs the above-mentioned operations through the focuslens operation member and the switching operation portion 25 whileobserving the fundus of the eye E to be inspected, which is displayed onthe monitor 30. Further, the examiner presses the imaging switch 42after performing the alignment and focusing. In the fundus camera, thexenon tube 3 emits light and the fundus of the eye E to be inspected isimaged on the imaging portion 22 through the observation/imaging opticalsystem, with the result that the image of the fundus of the eye E to beinspected can be obtained.

[Anterior Ocular Segment Imaging Mode]

In the case where the anterior ocular segment imaging mode is selected,the near-infrared LED 8 emits light to irradiate the anterior ocularsegment of the eye E to be inspected through the illumination opticalsystem.

At this time, the diopter adjustment switching portion 24 inserts thehigh-hyperopia diopter adjustment lens 16 into the observation/imagingoptical system in accordance with an operation of selecting the anteriorocular segment imaging mode, which is performed by the examiner throughthe switching operation portion 25.

Further, the diopter adjustment switching portion 24 of the funduscamera includes a diopter adjustment detecting portion 23 for detectinga state of the diopter adjustment portion 18, and a state of each of thefundus imaging mode and the anterior ocular segment imaging mode. Thediopter adjustment detecting portion 23 detects a current imaging modethat is selected through the operation performed by the examiner throughthe switching operation portion 25. In this case, the diopter adjustmentdetecting portion 23 detects that the anterior ocular segment imagingmode is selected. The diopter adjustment detecting portion 23 transmits,to the control portion 41, a signal indicating that the anterior ocularsegment imaging mode is selected, and the control portion 41 thereforemoves the focus lens 20 in a hyperopic direction through the driveportion 31.

After that, the examiner performs operations through the focus operationmember and the alignment operation portion while observing the anteriorocular segment of the eye E to be inspected, which is displayed on themonitor 30, to thereby perform focusing and alignment of the anteriorocular segment. Further, the examiner presses the imaging switch 42after finishing the alignment and focusing. In the fundus camera, thexenon tube 3 emits light and the anterior ocular segment of the eye E tobe inspected is imaged on the imaging portion 22 through theobservation/imaging optical system, with the result that the image ofthe anterior ocular segment of the eye E to be inspected can beobtained.

Next, a mechanism for selecting, by the examiner, the anterior ocularsegment imaging mode through the switching operation portion 25 of thediopter adjustment switching portion 24 is described in detail.

The switching operation portion 25 of the diopter adjustment switchingportion 24 is a rotary knob as illustrated in FIG. 2, and is rotatablein the arrow directions. The examiner adjusts the switching operationportion 25 to “0” in the case where the eye E to be inspected of thesubject is nearly emmetropic, “−” in the case where the eye E to beinspected of the subject is highly myopic, “+” in the case where the eyeE to be inspected of the subject is highly hyperopic, and “X” in thecase where the anterior ocular segment imaging mode is selected. Theswitching operation portion 25 is rotatable clockwise andcounterclockwise. Note that, the symbols for identifying the imagingmode and the like are not limited to the above-mentioned symbols, andmay be characters instead. Thus, the identification format is notlimited.

Further, as illustrated in FIG. 1, the switching operation portion 25has a diopter switching cam 19 coupled thereto, and the diopterswitching cam 19 rotates in synchronization with the switching operationportion 25. The diopter switching cam 19 has a cam mechanism, andinserts and removes the high-hyperopia diopter adjustment lens 16 andthe high-myopia diopter adjustment lens 17 held by the diopteradjustment portion 18 into and from the observation/imaging opticalsystem in accordance with the rotational position of the diopterswitching cam 19.

Further, the diopter switching cam 19 has a fundus/anterior ocularimaging switching lever 26 coupled thereto. The diopter switching cam 19moves the fundus/anterior ocular imaging switching lever 26 inaccordance with the rotational position of the diopter switching cam 19.Through the movement of the diopter adjustment portion 18 and thefundus/anterior ocular imaging switching lever 26, the diopteradjustment detecting portion 23 detects the state of the diopteradjustment lens, and at the same time, detects the state of each of thefundus imaging mode and the anterior ocular segment imaging mode.Referring to FIG. 3, a method of detecting the imaging mode and the likeby the diopter adjustment detecting portion 23 is described later.

Next, an operation to be performed in the fundus camera in a case wherethe examiner operates the switching operation portion 25 to rotate andchanges the selection from the state of the fundus imaging mode to thestate of the anterior ocular segment imaging mode is described.

First, the examiner operates the switching operation portion 25 torotate clockwise or counterclockwise, to thereby adjust the switchingoperation portion 25 to “X” indicating the anterior ocular segmentimaging mode.

Then, the diopter switching cam 19 coupled to the switching operationportion 25 performs rotational motion in synchronization with theswitching operation portion 25.

The diopter adjustment portion 18 abuts against a cam surface of thediopter switching cam 19. Accordingly, through the rotation of thediopter switching cam 19, the diopter adjustment portion 18 performstranslational motion to switch the state of the diopter adjustment lens.

Further, the fundus/anterior ocular imaging switching lever 26 abutsagainst the cam surface of the diopter switching cam 19. Accordingly,through the rotation of the diopter switching cam 19, thefundus/anterior ocular imaging switching lever 26 performs translationalmotion to switch to the state in which the anterior ocular segmentimaging mode is detected by the diopter adjustment detecting portion 23.

Now, referring to the schematic diagram of FIG. 3, a mechanism fordetecting the imaging of the myopic or hyperopic eye, or the imagingmode by the diopter adjustment detecting portion 23 is describedspecifically. As illustrated in FIG. 3, the diopter adjustment detectingportion 23 includes sensors P1 to P3 such as photoelectric sensorsarranged in parallel.

When the imaging mode is the fundus imaging mode and the adjustment lensis not inserted because of the imaging of the nearly emmetropic eye (inthe case of “0”), the fundus/anterior ocular imaging switching lever 26is positioned at the sensor P1, and a detection-subject portion 18 aformed on the diopter adjustment portion 18 is positioned at the sensorP2. Therefore, the diopter adjustment detecting portion 23 detects that“P1 is effective”, “P2 is effective”, and “P3 is ineffective”. The term“effective” herein refers to a state in which the sensor detects anobject. Further, in FIG. 3, when each of the sensors P1 to P3 iseffective, such a state is represented by a black triangle, and wheneach of the sensors P1 to P3 is ineffective, such a state is representedby a white triangle.

When the imaging mode is the fundus imaging mode and the high-myopiadiopter adjustment lens 17 is inserted because of the imaging of thehighly myopic eye (in the case of “−”), the fundus/anterior ocularimaging switching lever 26 is positioned at the sensor P1, and thedetection-subject portion 18 a is positioned between the sensor P2 andthe sensor P3. Therefore, the diopter adjustment detecting portion 23detects that “P1 is effective”, “P2 is ineffective”, and “P3 isineffective”.

When the imaging mode is the fundus imaging mode and the high-hyperopiadiopter adjustment lens 16 is inserted because of the imaging of thehighly hyperopic eye (in the case of “+”), the fundus/anterior ocularimaging switching lever 26 is positioned at the sensor P1, and thedetection-subject portion 18 a is positioned at the sensor P3.Therefore, the diopter adjustment detecting portion 23 detects that “P1is effective”, “P2 is ineffective”, and “P3 is effective”.

When the imaging mode is the anterior ocular segment imaging mode (inthe case of “X”), the fundus/anterior ocular imaging switching lever 26is positioned at the sensor P2, and the detection-subject portion 18 ais positioned at the sensor P3. Therefore, the diopter adjustmentdetecting portion 23 detects that “P1 is ineffective”, “P2 iseffective”, and “P3 is effective”.

In other words, the diopter adjustment detecting portion 23 detects thesensors P1 to P3 in the following detection pattern.

Fundus imaging mode, imaging of nearly emmetropic eye: P1: effective,P2: effective, P3: ineffective

Fundus imaging mode, imaging of highly myopic eye: P1: effective, P2:ineffective, P3: ineffective

Fundus imaging mode, imaging of highly hyperopic eye: P1: effective, P2:ineffective, P3: effective

Anterior ocular segment imaging mode: P1: ineffective, P2: effective,P3: effective

Through the rotational motion of the diopter switching cam 19, thediopter adjustment portion 18 and the fundus/anterior ocular imagingswitching lever 26 impose a change in the diopter adjustment detectingportion 23 in the above-mentioned detection pattern.

The diopter adjustment detecting portion 23 detects the state of thediopter adjustment lens, and the state of each of the fundus imagingmode and the anterior ocular segment imaging mode in accordance with thepattern. The diopter adjustment detecting portion 23 notifies thecontrol portion 41 of the state of the imaging mode, and therefore thecontrol portion 41 moves the focus lens 20 through the drive portion 31in accordance with the imaging mode. For example, when the examinerchanges the imaging mode from the fundus imaging mode to the anteriorocular segment imaging mode, the control portion 41 moves the focus lens20 in the hyperopic direction through the drive portion 31. In thiscase, the three sensors P1 to P3 are used to detect the state of thediopter adjustment lens and the state of the imaging mode, but thepresent invention is not limited to this case. Sensors may be arrangedat the respective rotational positions of the switching operationportion 25, to thereby detect the state of the diopter adjustment lensand the state of the imaging mode.

In this manner, the examiner only operates the switching operationportion 25 and adjusts the switching operation portion 25 to thespecified position of the anterior ocular segment imaging mode. Thus, inthe fundus camera, the diopter adjustment lens suitable to image theanterior ocular segment is set and the focus lens 20 is moved to thesuitable position.

After that, the examiner operates the alignment operation portion toperform the focusing and alignment operations for the anterior ocularsegment of the eye E to be inspected while observing the monitor 30.Further, the examiner presses the imaging switch 42 after performing thealignment and focusing. In the fundus camera, the anterior ocularsegment of the eye E to be inspected is imaged, with the result that theimage of the anterior ocular segment of the eye E to be inspected can beobtained.

According to this embodiment, the switching operation portion 25 that iscapable of selecting the fundus imaging mode or the anterior ocularsegment imaging mode is provided. Thus, the examiner can realize thefundus imaging mode or the anterior ocular segment imaging mode throughdistinct selection, with the result that the fundus imaging and theanterior ocular segment imaging is clearly distinguished from eachother. Further, the state of each of the diopter adjustment switchingportion 24 and the focus lens 20 is switched to a suitable state inaccordance with the imaging mode selected by the switching operationportion 25, and thus the switching operation of the examiner can beperformed simply.

Further, at the time of the anterior ocular segment imaging, in thediopter adjustment switching portion 24, it is necessary to use thehigh-hyperopia diopter adjustment lens 16 as the diopter adjustmentportion 18. In this embodiment, the diopter adjustment switching portion24 is identical with the switching operation portion 25, and hence thereis no need to separately provide any drive system for diopter adjustmentswitching (switching for hyperopia) at the time of the anterior ocularsegment imaging. As a result, the configuration for switching to theanterior ocular segment imaging can be simplified.

Second Embodiment

FIG. 4 is a view illustrating an overall configuration of thenon-mydriatic fundus camera. A configuration of an optical main body 100is the same as the configuration of FIG. 1, and description thereof istherefore omitted herein. In FIG. 4, the front side of the fundus camerais represented by “Fr”, and the rear side thereof is represented by“Rr”.

The fundus camera includes a fixed base 102 having a face receivingportion 101 fixed to the front side thereof, the face receiving portion101 supporting the face of the subject, and a movable stage 103 movableon the fixed base 102 from front to back and from side to side, andhaving the optical main body 100 mounted thereto. Further, the funduscamera includes an alignment operation portion 104 for operating themovable stage 103.

When the examiner operates the alignment operation portion 104, themovable stage 103 and the optical main body 100 move from front to backand from side to side in association with each other.

In the case of performing the anterior ocular segment imaging, asdescribed in the first embodiment, the diopter switching cam 19 insertsthe high-hyperopia diopter adjustment lens 16 of the diopter adjustmentportion 18 into the observation/imaging optical system, and the controlportion 41 moves the focus lens 20 toward the hyperopic side. In thisembodiment, in a case where the focus is not achieved on the anteriorocular segment of the eye E to be inspected even through theabove-mentioned operation, the examiner can operate the alignmentoperation portion 104 to move the movable stage 103 toward the examinerside.

Further, as illustrated in FIG. 4, the fundus camera of this embodimentincludes, in any one of the fixed base 102 and the movable stage 103, analignment detecting portion 105 for detecting the position of themovable stage 103 in the back-and-forth direction, and a selection driveportion (not shown) as an imaging selection drive unit. The alignmentdetecting portion 105 and the selection drive portion are eachelectrically connected to the control portion 41 illustrated in FIG. 1.The selection drive portion rotates the diopter switching cam 19.

Under a state in which the fundus imaging mode is selected as theimaging mode, at the time of the anterior ocular segment imaging, theexaminer needs to greatly move the movable stage 103 toward the examinerside (rearward) in order to image the anterior ocular segment. When theexaminer operates the alignment operation portion 104 to move themovable stage 103 toward the examiner side, the alignment detectingportion 105 detects the position of the movable stage 103 after themovable stage 103 moves by a predetermined distance, and transmits asignal (detection information) to the control portion 41. The controlportion 41 moves the focus lens 20 toward the hyperopic side through thedrive portion 31 so that the anterior ocular segment can be imaged.Further, the control portion 41 rotates the diopter switching cam 19through the selection drive portion to insert the high-hyperopia diopteradjustment lens 16 into the observation/imaging optical system. Afterthat, the examiner presses the imaging switch 42 to image the anteriorocular segment of the eye E to be inspected in the fundus camera, withthe result that the image of the anterior ocular segment of the eye E tobe inspected can be obtained.

In this embodiment, the alignment detecting portion 105 serving as amovable stage detecting unit for detecting the position of the movablestage 103 is provided, and based on the output therefrom, the state ofeach of the diopter adjustment switching portion 24 and the focus lens20 is switched to a suitable state. Thus, the anterior ocular segmentimaging can be performed only by operating the movable stage 103, and asa result, the switching between the fundus imaging and the anteriorocular segment imaging can be simplified.

As described above, according to the first and second embodiments, thefundus imaging mode and the anterior ocular segment imaging mode can beselected clearly and distinctly. In addition, the switching operationfrom the fundus imaging mode to the anterior ocular segment imaging modecan be minimized, with the result that the anterior ocular segmentimaging can be performed comfortably.

Hereinabove, the present invention has been described with reference tovarious exemplary embodiments, but the present invention is not limitedonly to those embodiments, and modifications and the like may be madewithin the scope of the present invention.

For example, the second embodiment has described the case where theexaminer operates the alignment operation portion 104 to move themovable stage 103 toward the examiner side in order to image theanterior ocular segment, but the present invention is not limited tothis case. For example, the same configuration may be employed for acase where the examiner operates the alignment operation portion 104 tomove the movable stage 103 toward the subject side when the examinerimages the fundus after imaging the anterior ocular segment.Specifically, the alignment detecting portion 105 detects the positionof the movable stage 103 after the movable stage 103 moves toward thesubject side by a predetermined distance, and transmits a signal to thecontrol portion 41. The control portion 41 moves the focus lens 20toward the myopic side through the drive portion 31 so that the funduscan be imaged. Further, the control portion 41 rotates the diopterswitching cam 19 through the selection drive portion to the position ofthe fundus imaging mode.

Further, the present invention is also implemented by executing thefollowing processing. Specifically, in this processing, software(program) for implementing the functions of the above-mentionedembodiments is supplied to a system or an apparatus via a network orvarious kinds of storage medium, and a computer (or CPU, MPU, etc.) ofthe system or the apparatus reads and executes the program.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2010-194751, filed Aug. 31, 2010, which is hereby incorporated byreference herein in its entirety.

What is claimed is:
 1. A fundus imaging apparatus, comprising: animaging unit for receiving reflected light from an eye to be inspectedthrough an optical system to take an image of the eye to be inspected; afocusing unit for achieving a substantially conjugate relationshipbetween the eye to be inspected and the imaging unit; a diopteradjustment unit for adjusting a diopter when the eye to be inspected ismyopic or hyperopic; an imaging selecting unit capable of selecting oneof a fundus imaging mode, in which a fundus of the eye to be inspectedis imaged, and an anterior ocular segment imaging mode, in which ananterior ocular segment of the eye to be inspected is imaged; a diopteradjustment switching unit for switching the diopter adjustment unit inaccordance with the one of the fundus imaging mode and the anteriorocular segment imaging mode selected by the imaging selecting unit; anda drive unit for driving the focusing unit in accordance with the one ofthe fundus imaging mode and the anterior ocular segment imaging modeselected by the imaging selecting unit.
 2. A fundus imaging apparatusaccording to claim 1, wherein the diopter adjustment switching unitmoves in association with the imaging selecting unit, and wherein thediopter adjustment unit is inserted into and removed from the opticalsystem in accordance with a position selected by the imaging selectingunit.
 3. A fundus imaging apparatus according to claim 2, wherein, whenthe anterior ocular segment imaging mode is selected by the imagingselecting unit, the diopter adjustment switching unit inserts ahyperopia diopter adjustment lens held by the diopter adjustment unitinto the optical system.
 4. A fundus imaging apparatus according toclaim 1, wherein, when the fundus imaging mode is selected by theimaging selecting unit, the drive unit drives the focusing unit toward amyopic side, and wherein, when the anterior ocular segment imaging modeis selected by the imaging selecting unit, the drive unit drives thefocusing unit toward a hyperopic side.
 5. A fundus imaging apparatusaccording to claim 2, wherein the diopter adjustment switching unitcomprises a cam mechanism, wherein the fundus imaging apparatus furthercomprises: a switching lever positionally changeable in association withthe cam mechanism; and a detecting unit for detecting a position of theswitching lever and a position of the diopter adjustment unit, andwherein the drive unit drives the focusing unit based on detectioninformation obtained through the detection performed by the detectingunit.
 6. A fundus imaging apparatus according to claim 1, furthercomprising: a movable stage having the imaging unit mounted thereto, themovable stage being capable of moving the imaging unit toward one of amyopic side and a hyperopic side with respect to the eye to beinspected; and a movable stage detecting unit for detecting a positionof the movable stage, wherein the drive unit drives the focusing unit inaccordance with the position of the movable stage detected by themovable stage detecting unit.
 7. A fundus imaging apparatus according toclaim 6, further comprising an imaging selection drive unit for drivingthe imaging selecting unit, wherein the imaging selection drive unitdrives the imaging selecting unit to select the one of the fundusimaging mode and the anterior ocular segment imaging mode in accordancewith the position of the movable stage detected by the movable stagedetecting unit.
 8. A method of controlling a fundus imaging apparatus,the method comprising: selecting one of a fundus imaging mode, in whicha fundus of an eye to be inspected is imaged, and an anterior ocularsegment imaging mode, in which an anterior ocular segment of the eye tobe inspected is imaged; adjusting a diopter of the eye to be inspectedwhich is myopic or hyperopic in accordance with the selected one of thefundus imaging mode and the anterior ocular segment imaging mode; anddriving a focusing unit in accordance with the selected one of thefundus imaging mode and the anterior ocular segment imaging mode.
 9. Arecording medium having a program recorded thereon, the program causinga computer to execute the selecting, the adjusting, and the driving ofthe method of controlling a fundus imaging apparatus according to claim8.